The robber – who was given 13 life terms – grabbed a bag of cash the robber smashed his way out through the back of the building.

Ibby Sumer, the manager of the Golden Grill nearby in Sunbury said: "We've just heard from customers that it's this guy from Twickenham. The Skull Cracker, that's the name they said.

"That's what one customer said. They said he ran through the back behind the building society past my café after escaping the building society.

SKULL CRACKER: Wheatley got his nickname after attacking witnesses to his robberies [ENTERPRISE]

"I heard a smashing noise and ran round the back gates. I didn't see anything but he must have just run past our shop.

"I think he smashed his way out the back door of the building society. "I must have just missed him. I'm glad I did though.

"The customers said it was an armed robbery. They say he ran off with some cash."

Another eyewitness, who refused to be identified, said: "I didn't see the robbery, but saw all the police down there immediately afterwards. I spoke to a copper and he said they thought it was the Skull Cracker."

Wheatley was last seen in the Strawberry Hill area of Twickenham after police raided a property there on Monday.

The 55-year-old, who was serving 13 life sentences for 13 raids on banks and building societies over 10 months in 2001 and 2002 and escaped during day release HMP Standford Hill. "It's not really a safe area," added Mr Sumer. "The girls that were working in the building society looked really shaken up, it must have been absolutely terrifying."

DANGEROUS: The fake gin that Wheatley used in his robberies [ENTERPRISE]

A Surrey police spokesman said: "At 10.20 today Surrey Police responded to reports of an armed robbery at a building society in Sunbury. The incident took place at the Chelsea Building Society at The Parade, Staines Road. "Officers including specialist firearms officers are currently at the scene.

"The investigation is on going. We are looking at a number of avenues in the investigation. Obviously with the recent set of events we can't say categorically, either way, if it is Michael Wheatley.

"Officers are still at the scene, they are carrying out initial inquiries, it is too early to call."

A spokesperson for Chelsea Building Society said: "We can confirm there was a robbery at our Sunbury branch this morning. We are helping the police with their inquiries. Nobody was hurt in the incident but staff were understandably shaken and upset.

The branch remains closed currently and we hope to reopen as soon as possible."